Micrometer gauge



y April 5, 1927.4

1,623,574 w. l.. BRYANT A MICROMETER GAUGE originar Filed Nov. 18. 1922 Patented Apr. 5, 1927.

UNITED STATES WILLIAM L. BRYANT, F SPRINGFIELD, VERMONT.

IIMT.CROIMETEIR. GAUGE.

Original application led November 18, 1922, Serial No. 601,731. Divided and-this application med J'iily 6, 1925. Serial No. 41,553.

This invention relates to gauges ot that type in which the measuring indication is made by the length ot a column of liquid in a graduated capillary tube. The subject matter of this present application relates to devices for measuring outside diameters, being divided out from my application for patent Serial No. 601,731, tiled November 18, 1922, for micrometer gauges.

For a more complete understanding of this application reference may be had to the accompanying drawings in which Figure 1 is a side elevation partly in seetion of the gauge.

Figure 2 is a section on line 2 2 of Figure 1.

In these figures the handle portion of the instrument is formed by means of a capillary tube 90 one end of which as at 91 is bent to extend at right angles to the main portion of the tube so that the tube is L shaped. This bent portion has its end 92 threaded for the reception of a cylindrical cap or housing 93 adapted to contain the liquid reservoir` 94 against which iinpinges the inner end of a work-engaging pin 95. This pin may be held in position by means of a leaf spring 96 engaging it at one end and made fast at its opposite end at 97 to the portion 93. In this I form also a threaded plug 98 may be em'- ployed to adjust the initial length of the liquid column in the capillary tube 90. The oppositil end ot this capillary tube is reduced as shown at 99 for engagement with a cap 100 which houses the gas reservoir 101 and inthe end of which is threaded the adjusting plug 102. By which the capacity ot the gas reservoir may be adjustcd- The reservoir 91 being supplied with liquid, and the parts being assembled, decreasing the capacity of this reservoir somewhat causes the liquid therein to extend therefrom as a column within the capillary tube. .This decrease of capacity is eitected to such an extent as to cause this column to extend Within the capillary tube to any desired convenient distance. Slidably mounted on the main portion of the capillary tube is a bracket member 105 having a handle portion 106 and an opening 107 therethrough through which the graduations on the capillary tube may be observed. (.)ppoSite to the handle portion 106 this member has an outwardly extending web 108 at the end ot which is an eye 109 for the reception of a micrometer screw 110. The iuiier end ot thisscrew is formed as an abutment 111 which is positioned opposite to the pin 95, the pin and the portion 111 forming the two work-engaging element-s of a pair of outside `r calipers. The bracket 105, as shown in Figure 2, is formed split, the slit portions 112 and 113 being adapted to be brought together f or clamping the bracket in any desired position lengthwise of the tube by means of a screw 114.

In the use of this c-:m of the instrument the' bracket is adjusted as close as possible to the desired position to bring the elements 95 and 111 the proper distance apart. The micrometer 4screw 110 is then adjusted so that the end of the liquid column will bein a convenient position when the proper size of Work has been reached, as it is being ground or otherwise finished, the Work position between the pin and abutment causing the .pin to compress the reservoir 94 to an extent indicated by the movement of the liquid column in the capillary tube.

In the drawing is shown also the idea of employing a capillary tube having two sizes of internal diameter, the end of the liquid column appearing in the portion of smaller diameter as the correct tinished size of the work is approached so that the accuracy of the instrument may be made greater at that time.

Having thus described one embodiment of this invention, it should be evident that many changes and modifications might be made therein without departing from its spirit or scope as defined by the appended claims.

I claim:

1. In a measuring instrument, a transparent graduated capillary tube, a bracket ineinber slidable thereon, means to clamp said. member 1n position, a micrometer screw car ried by said member, a flexible walled liquid reservoir connected to one end of said tube and communicating with the bore thereof, an element movable to engage said reservoir with more or less pressure and between which and said screw an' object to be measured may be placed, said.v reservoir being filled with a liquid extending as a liquid column iii said tube, and a gas pressure reservoir at the opposite end of said'tube cominunicating with the bore thereof.

2. In a measuring instrument, a transparent graduated capillary tube having one end portion turned at an an le to the remainder thereof, a eXible wal ed liquid reservoir connected to said turned end and communicatinor with the bore thereof, an element movable to engage said reservoir with more -or less pressure, a bracket slidable on said tube, rneans to clamp said bracket in posi- -tion thereon, an element carried by said bracket in alinement With said movable element, said elements receiving an object io be measured therebetween, and a gas pressure reservoir at the opposite end of said. tube and communicating with the bore thereof.

3. In a measuring instrument, an Lsliaped transparent graduated capillary tube having'threaded extremities, flexible Walled reservoirs at each end of said tube in communication with the bore thereof, a cap engaging each of said threaded ends and retaining said reservoirs in position, an element slidable through the side wall of one of said caps and engageable with the reservoir therein, a bracket adjustable fixed to said tube,and an element carried by said bracket in position to clamp an object against said f slidable element.

4. In a measuring instrument, anL shaped transparentgraduated capillary tube having threaded extremities, flexible Walled reservoirs at each end of said tube in communication with the bore thereof, a cap engaging each of said threaded ends and retaining said reservoirs in position, an element slidable through Ithe side Wall of one of said caps and enga cable with the reservoir therein, a bracket a justable xed to said tube, an element carried by said bracket in position to clamp an object a ainst said slidable element, and plugs adjustably carried by each of said caps and bearing on the reservoirs therein by which the capacities of said reservoirs may be adjusted.

5. 1n a measuring instrument, a transparent graduated capillary tube, a reservoir at each end of said tube in communication with the bore thereof, means for adjusting the capacities of each of said reservoirs, a bracket adjustable along said tube, an element movable to vary the capacity of one of :said reservoirs, and an element carried by said bracketin opposed relation to said movable element and between which elements an object to be measured may be placed.

In testimony whereof I have aixed my signature. 2 l

WILLIAM L. BRYANT. 

